Vehicle active network with fault tolerant devices

ABSTRACT

A vehicle active network ( 12 ) communicatively couples devices ( 14 - 20 ) within a vehicle ( 10 ). Device operation is independent of the interface ( 22 - 28 ) of the device ( 14 - 20 ) with the active network ( 12 ). Additionally, the architecture of the active network ( 12 ) provides one or more levels of communication redundancy. The architecture provides for the total integration of vehicle systems and functions, and permits plug-and-play device integration and upgradeability.

RELATED APPLICATIONS

The present invention is related to the following applications which areassigned to the same assignee as the present invention:

VEHICLE ACTIVE NETWORK, filed Aug. 31, 2001, having Ser. No. 09/945,581;

VEHICLE ACTIVE NETWORK WITH RESERVED PORTIONS, filed Aug. 31, 2001,having Ser. No. 09/944,892;

VEHICLE ACTIVE NETWORK WITH DATA REDUNDANCY, filed Aug. 31, 2001, havingSer. No. 09/943,908;

VEHICLE ACTIVE NETWORK WITH COMMUNICATION PATH REDUNDANCY, filed Aug.31, 2001, having Ser. No. 09/943,870;

VEHICLE ACTIVE NETWORK ADAPTED TO LEGACY ARCHITECTURE, filed Aug. 31,2001, having Ser. No. 09/945,585;

LINKED VEHICLE ACTIVE NETWORKS, filed Aug. 31, 2001, having Ser. No.09/944,653;

VEHICLE ACTIVE NETWORK WITH DATA ENCRYPTION, filed Aug. 31, 2001, havingSer. No. 09/944,883;

VEHICLE ACTIVE NETWORK AND DEVICE, filed Aug. 31, 2001, having Ser. No.09/944,887;

VEHICLE ACTIVE NETWORK WITH BACKBONE STRUCTURE, filed Aug. 31, 2001,having Ser. No. 09/943,921;

VEHICLE ACTIVE NETWORK TOPOLOGIES, filed Aug. 31, 2001, having Ser. No.09/944,891; and

DATA PACKET FOR A VEHICLE ACTIVE NETWORK, filed Aug. 31, 2001, havingSer. No. 09/943,914.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to the field of communication systemsfor vehicles such as automobiles and trucks, and more particularly, tocommunicatively coupling devices within the vehicle.

2. Description of the Related Art

Microprocessor technology has greatly improved the efficiency,reliability and safety of the automobile. Microprocessor devices haveenabled airbags, anti-lock brakes, traction control, adaptive suspensionand power train control just to name a few of the areas where processingtechnology has literally transformed the automobile. These systems,first provided by manufacturers only on the most expensive luxury andperformance automobiles, are now common and even standard equipment onthe most affordable economy models. Soon, control-by-wire applicationswill become equally commonplace. For example, throttle-by-wire has beensuccessfully implemented on a number of vehicle platforms. Steer-by-wireand brake-by-wire applications are not far behind. Alternative fuelvehicles, including fuel cell vehicles, electric and hybrid vehicleswill require still more sophisticated control applications, and hencestill more processing capability.

The automobile is simultaneously being enhanced by informationtechnology. Satellite navigation systems, voice and data communications,and vehicle telemetry systems inform the driver, entertain thepassengers and monitor vehicle performance. These systems can providedriving directions, identify points of interest along the driver'sroute, remotely diagnose and/or predict vehicle problems, unlock thedoors, disable the vehicle if stolen or summon emergency personnel inthe event of an accident.

The growing amount and level of sophistication of vehicle orientedinformation technology presents the challenge to the automotive engineerto implement and integrate these technologies with existing and emergingvehicle systems in an efficient manner. Current design philosophycenters on the incorporation of one or more vehicle communication busstructures for interconnecting the various control elements, sensors,actuators and the like within the vehicle. The design of these busstructures is often driven by compliance with governmental regulationssuch as second-generation on-board diagnostics (OBD-II) and federalmotor vehicle safety standards (FMVSS). These structures offer limitedability to adapt new technology to the vehicle. Moreover, given thetypical four-year design cycle and ten-year life cycle of an automobile,the technology within a vehicle may become significantly obsolete evenbefore the vehicle is brought to market, and the bus architecture leavesthe owner little ability to adapt new technology to the vehicle.Notwithstanding these limitations, the bus architecture offers agenerally reliable, relatively fast platform for linking electronicdevices and systems within the vehicle.

To link vehicle system technologies with vehicle informationtechnologies, there has been proposed to incorporate a networkarchitecture within the vehicle. For example, published PatentCooperation Treaty (PCT) application number WO 00/77620 A2 describes anarchitecture based on the Ethernet wherein devices within the vehicleare coupled to the network. This publication describes a networkincluding a cable backbone to which the devices are coupled and anetwork utility for controlling communications between the devices overthe network. Important to note is that the proposed network does notintegrate the vehicle systems, but instead is adapted to provide aplatform for adding information technologies, such as pagers, personaldigital assistants, navigations, etc. technologies to the vehicle. Thepower train, suspension, braking and airbag systems, as examples,utilize a vehicle bus for data communications, and these systems operateautonomously of the network described in the publication. A bridge orgateway is provide to couple the vehicle bus to the network as a deviceor client allowing data sharing between the bus and the network, but thedata communication needs of the vehicle systems are not serviced by thenetwork. A reason that these systems are designed to operateautonomously of the described network is that they have time critical,system critical data requirements that cannot be met by the networkstructure described. Additionally, the network described in thepublication suffers from numerous single points of failure, such as ifthe cable backbone is disrupted or the network utility fails.

Thus there is a need for an architecture for automotive electronicsystems that facilitates the efficient, reliable integration ofin-vehicle electronic technologies and plug-and-play upgradeability.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described in terms of the several preferred embodimentsset out fully below and with reference to the following drawings inwhich like reference numerals are used to refer to like elements throughout.

FIG. 1 is a block diagram illustration of an embodiment of a vehicleactive network according to the invention.

FIG. 2 is a block diagram illustration of the vehicle active networkshown in FIG. 1 illustrating multiple communication path capability ofthe vehicle active network.

FIG. 3 is a block diagram illustration of an alternate embodiment of avehicle active network.

FIG. 4 is a graphic illustration of an embodiment of the vehicle activenetwork according to the invention.

FIG. 5 is a graphic illustration of a portion of the vehicle activenetwork illustrated in FIG. 4 illustrating propagation of timinginformation throughout the network.

FIG. 6 is a graphic illustration of an alternate embodiment of athree-dimensional vehicle active network.

FIG. 7 is a graphic illustration of an alternate embodiment of a vehicleactive network according to the invention incorporating a No-Go zone.

FIG. 8 is a graphic illustration of an embodiment of a vehicle activenetwork according to the invention providing packet redundancy.

FIG. 9 is a schematic illustration of an embodiment of an active networkelement according to the invention.

FIG. 10 is a schematic illustration of an embodiment of a vehicle activenetwork including a device forming a portion of the vehicle activenetwork.

FIG. 11 is a schematic illustration of an alternate embodiment of avehicle active network including a device forming a portion of thevehicle active element.

FIG. 12 is a schematic illustration of an alternate embodiment of avehicle active network including a device forming a portion of thevehicle active element.

FIG. 13 is a schematic illustration of an alternate embodiment of avehicle active network including a device forming a portion of thevehicle active element.

FIG. 14 is a block diagram illustration of linked active networksaccording to an alternate embodiment of the invention.

FIG. 15 is a block diagram illustration of linked active networksaccording to an alternate embodiment of the invention.

FIG. 16 is a graphic illustration of an alternate embodiment of avehicle active network according to the invention incorporating a coreportion.

FIG. 17 is a graphic illustration of an alternate embodiment of avehicle active network illustrating adaptable scalability.

FIG. 18 is a graphic illustration of an alternate embodiment of avehicle active network illustrating adaptable scalability.

FIG. 19 is a block diagram illustration of a topology for a vehicleactive network according to a preferred embodiment of the invention.

FIG. 20 is a block diagram illustration of a topology for a vehicleactive network according to an alternate preferred embodiment of theinvention.

FIG. 21 illustrates various data packets that may be adapted for usewith a vehicle active network according to the preferred embodiments ofthe invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An architecture for automotive functional systems according to theinvention is based upon inter-networking and computing principles. Thearchitecture incorporates a vehicle active network for communicativelycoupling devices within the vehicle. Device operation is independent ofthe interface of the device with the active network. Additionally, thearchitecture of the active network provides one or more levels ofcommunication redundancy. The architecture provides for the totalintegration of vehicle systems and functions, and permits plug-and-playdevice integration, scalability and upgradeability.

The active network may include a plurality of communicatively coupledactive elements, which permit communication between devices coupled tothe active network without a network utility or arbiter. The activeelements enable multiple simultaneous communication paths betweendevices within the vehicle. The multiple simultaneous communicationpaths may include a variety of potential paths among the activeelements, including, for example, alternative paths responsive tonetwork status, redundant paths or even a loop having a loop data ratedifferent from a path data rate of other communication paths.

The active network may be based upon packet data principles andimplement any suitable packet data transmission protocol. Suitablepacket data protocols include, but are not limited to, transmissioncontrol protocol/Internet protocol (TCP/IP), asynchronous transfer mode(ATM), Infiniband, and RapidIO. Each of these protocols, whenimplemented in an active network according to the various embodiments ofthe invention, permits one or more levels of redundant communicationcapability to ensure reliable data transfer while permitting activesystem diagnostics and fault tolerance.

The active network may incorporate a fabric of active network elementscommunicatively coupling the devices. The fabric permits multiplesimultaneous peer-to-peer communications. The active network elementsmay be arranged in, for example, an array topology, a multi-droptopology, or an asymmetric topology. Furthermore, the architecture mayincorporate one or more levels of wireless communication. For example,the architecture supports peer-to-peer, one-to-many broadcast,many-to-many broadcast, intra-network and inter-network communications,device to network, vehicle-to-vehicle and vehicle to remote stationwireless communications.

Many additional advantages and features of the invention will beapparent from the description of the various preferred embodiments. Atthe outset it is important to point out that the invention is describedin terms of embodiments implemented within a vehicle, or moreparticularly, an automobile. The terms vehicle and automobile as usedherein may include automobiles, trucks, buses, trailers, boats,airplanes, trains and the like. Therefore, references to vehicle orautomobile apply equally to virtually any type of commercially availablevehicle.

FIG. 1 illustrates a vehicle 10 including an active network 12 to whichvarious vehicle devices 14-20 are coupled via respective interfaces22-28. The devices may be sensors, actuators and processors used inconnection with various vehicle functional systems and sub-systems, suchas, but not limited to, control-by-wire applications for throttle,braking and steering control, adaptive suspension, power accessorycontrol, communications, entertainment, and the like.

The interfaces 22-28 are any suitable interface for coupling theparticular device to the active network 12, and may be wire, optical,wireless or combinations thereof. The interfaced device is particularlyadapted to provide one or more functions associated with the vehicle.These devices may be data producing, such as a sensor, data consuming,such as an actuator, or processing, which both produces and consumesdata. Of course, an actuator, typically a data-consuming device, mayalso produce data, for example where the actuator produces dataindicating it has achieved the instructed state, or a sensor may consumedata, for example, where it is provided instructions for the manner offunction. Data produced by or provided to a device, and carried by theactive network 12, is independent of the function of the device itself.That is, the interfaces 22-28 provide device independent data exchangebetween the coupled device and the active network 12.

The active network 12 defines a plurality of communication paths 30between the devices. The communication paths 30 permit multiplesimultaneous peer-to-peer, one-to-many, many-to-many, etc.communications between the devices 14-20. Illustrated in FIG. 1, acommunication path 32, illustrated by the bold arrowed lines, may beformed between device 14 and device 20. This is not the onlycommunication path available for communications between devices 14 and20. Illustrated in FIG. 2, a path 34 may also couple devices 14 and 20.During operation of the vehicle 10, data exchanged between devices 14and 20 may utilize paths 32 and 34 or other paths between the devices.In operation, a single path may carry all of a single data communicationbetween the device 14 and the device 20, or several communication pathsmay carry portions of the data communication. Subsequent communicationsmay use the same path or other paths as dictated by the then state ofthe active network 12. This provides reliability and speed advantagesover bus architectures that provide single communication paths betweendevices, and hence are subject to failure with failure of the singlepath. Moreover, communications between other of the devices 14-20 mayoccur simultaneously using the communication paths 30.

The active network 12 may comply with transmission controlprotocol/Internet (TCP/IP), asynchronous transfer mode (ATM),Infiniband, RapidIO, or other packet data protocols. As such, the activenetwork 12 utilizes data packets, having fixed or variable length,defined by the applicable protocol. For example, if the active network12 uses asynchronous transfer mode (ATM) communication protocol, ATMstandard data cells are used.

The devices 14-20 need not be discrete devices. Instead, the devices maybe systems or subsystems of the vehicle and may include one or morelegacy communication media, i.e., legacy bus architectures such as CAN,LIN, FLEXRAY or similar bus structures. In such embodiments, therespective interface 22-28 may be configured as a proxy or gateway topermit communication between the active network 12 and the legacy device14-20. Alternatively, and referring to FIG. 3, the device 18 of thevehicle 10 is communicatively coupled via an interface 3 5 to a busarchitecture 33. The bus architecture 33 is then coupled via theinterface 26 to the active network 12. The bus architecture may be aCAN, LIN, FLEXRAY or similar bus structure.

Referring to FIG. 4, an active network 36 in accordance with analternate embodiment of the invention includes a fabric 38 of activenetwork elements 40 communicatively coupling a plurality of devices44-50 via respective interfaces 52-58. Connection media 42 interconnectsthe active network elements 40. The connection media 42 may be boundedmedia, such as wire or optical fiber, unbounded media, such as freeoptical or radio frequency, or combinations thereof. In addition, theterm active network element is used broadly in connection with thedefinition of the fabric 38 to include any number of intelligentstructures for communicating data packets within the active network 36without an arbiter or other network controller and may include:switches, intelligent switches, routers, bridges, gateways and the like.Data is thus carried through the network 36 in data packet form guidedby the active elements 40.

The cooperation of the active elements 40 and the connection media 42define a plurality of communication paths between the devices 44-50 thatare communicatively coupled to the active network 36. For example, aroute 60 defines a communication path from device 44 to device 50. Ifthere is a disruption 61 along the route 60 inhibiting communication ofthe data packets from the device 44 to the device 50, for example, ifone or active elements are at capacity or have become disabled or thereis a disruption in the connection media joining the active elementsalong the route 60, a new route, illustrated as route 62, can be used.Route 62 may be dynamically generated or previously defined as apossible communication path, to ensure the communication between thedevice 44 and the device 50.

In some applications, it may be necessary to provide synchronizedactivity, which requires timing information be available within theactive network. FIG. 5 illustrates a portion 80 of an active networkthat includes a fabric 82 of active elements 84. Connection media 86interconnects the active elements 84. Active element 88 is defined as aroot node or a root element. A spanning tree algorithm may be used inassociation with the active network to define the plurality ofcommunication paths available within the active network. The pluralityof communication paths may be defined by the spanning tree algorithmduring an initial configuration, or may be defined by a running of thespanning tree algorithm during each power on cycle or by other periodicrunning of the spanning tree algorithm. Timing may be propagated fromthe root node element 88 in the form of timing messages 90 from the rootnode, active element 88, to each of the active elements 84 via theplurality of communication paths. From the root node, the spans ofconnecting media 86 between each active element 84, and hence any delayin clock cycles in such spans, is known, and therefore from the rootnode precise timing may be established at each of the active elements 84and likewise at each of the devices coupled to the active network.Timing within the active network may be absolute, or may bedifferential.

Differential, or relative, timing is possible based on the configurationof the active network and the data packets. The point-to-pointconnections within the active network allow accurate calculation of timeto traverse the network. Thus, one is able to know when a packet wasgenerated based upon the point in the network it started at, the routeit took, and when it arrived at the current point. The time the packetwas generated is thus, “now” minus x units of time, where the x units oftime is the known time based on the route. In this scenario for timing,a central or root node may not be required.

Timing information within the network may degrade, for example as theresult of clock skew. Having the root node send periodic timing messagesrefreshes the timing information. Data packets communicated within theactive network may also contain timing information allowing individualdevices to update the timing information on an ongoing basis. Of course,the data packets may also contain timing information to indicate whencertain activities are to take place, or to indicate the freshness ofthe information. Other methods for establishing timing within the activenetworks apart from the root node concept may be employed.

FIG. 6 illustrates an active network 100 including a fabric 102 ofactive network elements 104 arranged in a three-dimensionalconfiguration. Connection media 106 communicatively couples the activenetwork elements 104. The connection media may be wire, optical, radiofrequency or combinations thereof. The three-dimensional configurationof fabric 102 may be used in connection with virtually any of theembodiments of an active network in accordance with the invention, anddemonstrates the flexibility and scalability of such active networks.

FIG. 7 illustrates the active network 36 (FIG. 4) modified to include aNo-Go zone 64. The No-Go zone 64 exclusively reserves a portion of thefabric 38, namely the active elements and connection media containedwithin the No-Go zone 64, for communication of data between device 46and the device 48. The No-Go zone 64 may reserve a sufficient portion ofthe fabric 38 to provide a plurality of possible communication pathsbetween the devices 46 and 48, or may reserve a single communicationpath. The No-Go zone 64 may be configured to carry data packets to/fromthe device 46 and to/from the device 48 to the exclusion of any otherdata packets. Alternatively, the No-Go zone 64 may be available forcommunication of data packets to/from any device provided that datapackets to/from devices 46 and 48 have transmission priority. Stillfurther, criteria may be established relating to the use of the No-Gozone 64 to transmit data to/from devices other than devices 46 and 48.For example, where a fault in the switch fabric requires use of theNo-Go zone 64 or where the non-exclusive use of the No-Go zone 64 doesnot exceed a threshold percentage of the overall capacity of the No-Gozone.

The No-Go zone 64 provides assured communication capability between thedevices associated with the No-Go zone 64. For example, if the devices46 and 48 are associated with a steer-by-wire application, propervehicle function requires that the data for this application betransmitted to the appropriate devices. Providing priority to the datapackets associated with the steer-by-wire application and transmittingthem within the switch fabric 38 generally may not sufficiently ensurethe data packets are timely delivered. However, reserving a portion ofthe switch fabric 38, i.e., the No-Go zone 64, provides the advantagesof a hard connection between the devices while preserving theflexibility of utilizing the entire switch fabric 38, if needed, shoulda fault occur within the No-Go zone 64. While described in connectionwith the active network 36 illustrated in FIG. 4, the concept of theNo-Go zone may be applied to any of the active network architecturescontemplated by the invention, including those shown in the embodimentsillustrated in FIGS. 1 and 2. Furthermore, while the No-Go zone 64 isshown as two-dimensional in FIG. 7, the No-Go zone 64 may correspond indimension to that of the fabric of active network elements. Also, theNo-Go zone 64 may be dynamically redefined during operation of thevehicle.

The multi-path architecture of the active network 12 and the activenetwork 36 permits fault tolerance and fault diagnosis to be easilyincorporated via data stream replication. Fault tolerance may beprovided using replicated data packets sent along the same communicationpath or multiple data paths. An embodiment wherein data packets arereplicated and transmitted along redundant paths is illustrated in FIG.8, which again depicts the active network 36. Device 46 iscommunicatively coupled to the fabric 38 by interface 54. At switchelement 66, data packets received from the device 44 are replicated,forming two streams of data packets (data streams). Of course more thantwo data streams may be generated, and additional data streams addadditional levels of redundancy. The data streams are transmitted fromthe device 44 to the device 50 via different communication paths, andpaths 68 and 70 are two of the numerous possible paths that may beformed in the switch fabric 38 from the device 46 to the device 50. Notall data packets need to travel on the same path, and the paths 68 and70 merely illustrate the concept of the redundant paths. The redundancyprovided by the two data streams (replicated data packets) enhancesreliability because a failure or disruption of one of the streams doesnot completely interrupt transmission of the data between the devices.Moreover, by monitoring receipt of the data streams at the device 50 itis possible to determine whether a fault exists in the fabric 38, and toisolate the fault to a region of the fabric 38. That is, the fault willlie on one of the two paths 68 and 70 on which the transmission of therespective data stream failed. Additionally, performance of the fabric38 may be measured based upon time of arrival data of the two datastreams.

FIG. 9 illustrates an active element 110 that may be used in connectionwith the fabric 38. To illustrate the functionality and the adaptabilityof the active element 110, it is shown to include a plurality of inputports 112, output ports 114 and input/output ports 116 and 118. Variousconfigurations of the active element 110 having more or fewer ports maybe used in an active network depending on the application. The activeelement 110 may further include a processor 120 coupled with a memory122. The processor 120 includes a suitable control program for effectingthe operation of the active element 110 for coupling inputs to outputsin order to transmit data packets within fabric 38.

The simplex input ports 112 and output ports 114 may be adapted foroptical media, while the duplex input/output ports 116 and 118 may beadapted for electrical media. Additionally, the active element 110 mayinclude a radio frequency (RF) transceiver 124 for RF transmission ofdata packets to other switch elements within the switch fabric 38 and toswitch elements of other active networks, for example active networkslocated in nearby vehicles. The switch element 110 may be an assembly ofcircuit components or may be formed as a single integrated circuitdevice.

FIG. 10 illustrates an alternate embodiment providing fault toleranceand fault detection. As illustrated in FIG. 8, a single interface 52couples the device 44 to the fabric 38. Failure of the interface 52would result in the device 44 becoming uncoupled from the fabric 38.Referring then to FIG. 10, a portion 130 of a fabric, such as fabric 38,includes a plurality of active elements 132 communicatively coupled byconnecting media 134. A device 136 is communicatively coupled to theportion 130. The device 136 includes an active element 138 integral tothe device, and providing a plurality of input/output ports. Theplurality of input/output ports, three of which are illustrated in FIG.10, couple to interfaces 140, 142 and 144. The interfaces 140, 142 and144 are communicatively coupled to switch elements 146, 148 and 150,respectively, of the portion 130. In this manner, the device 136 iscommunicatively coupled via a plurality of communication paths to theportion 130 of the fabric. Data streams may be communicated along eachof the communication paths to a destination device. This addsreliability by providing redundant paths from the device 136 to thefabric. It is also possible to determine the existence and locations offaults and fabric performance by monitoring the receipt of the datastreams at the destination device along each of the plurality ofcommunication paths.

In FIG. 11, the device 136 of FIG. 10 has been replaced by a sub-system152. The sub-system 152 includes a plurality of devices 154-158 that arecoupled via interfaces 160-164, respectively, to an active element 166within the device 136. The active element 166 is then coupled to theportion 130 of the fabric. The active element 166 may couple datastreams from one or more of the devices 160-164 to the portion 130.Moreover, the data streams may be coupled on multiple communicationpaths 140-144 to the portion 130.

In FIG. 12, the device 170 includes redundant elements 172 and 174. Thatis, each of elements 172 and 174 are designed to provide the requiredfunction of the device 170. In addition to providing a vehicle-relatedfunction, the device 170 also includes device elements 176 and 178,i.e., active network elements integrated within the device 170 whichalso form a portion of the active network. The device elements 176 and178 are coupled to active elements 146 and 148 of the portion 130. Thedevice elements 172 and 174 are also coupled to each of the activeelements 176 and 178 within the device 170 via connection media 184.Redundant function and redundant coupling of the device 170 to thefabric is provided by this arrangement ensuring that failure of eitherdevice elements 172 or 174 and/or failure of active elements 176 and 178and/or active elements 146 and 148 will not cause a loss of the functionof the device 170.

In FIG. 13, the system 180 includes devices 182, 184 and 186. Each ofdevices 182-186 may be designed to provide the same function, i.e.,triple redundancy, or may provide separate functions. The system 180also includes device elements 188-192. The device elements 188-192 arerespectively coupled to active elements 146-150 of the portion 130. Thedevice elements 188-192 are also coupled to each other by connectionmedia 183-187. Thus, triply redundant function and coupling is provided.

FIG. 14 illustrates wireless coupling of active networks acrossvehicles. A first vehicle 200 includes an active network 202 including aplurality of active elements, two of which are indicated as 204 and 206.All of the active elements, including the elements 204 and 206, arecommunicatively coupled via media 208. A second vehicle 210 includes anactive network 212 including a plurality of active elements, two ofwhich is indicated as 214 and 216. All of these active elements,including the active elements 214 and 216, are communicatively coupledvia media 218. Each of the active elements 204 and 206 includes wirelesscommunication capability, and similarly, each of the active elements 214and 216 includes wireless communication capability. For example, theactive elements 204, 206 and 214, 216 may incorporate a radio frequencytransceiver permitting these devices to communicate via radio frequencytransmissions.

As shown in FIG. 13, the active element 204 is communicatively coupledwith the active element 214 via radio frequency transmissions 220, andthe active element 206 is communicatively coupled with the activeelement 216 via radio frequency transmissions 222. In this manner,multiple vehicles may be linked via the active elements disposed withinthe active networks. Linking the active networks in this mannereffectively expands the active networks of both vehicles, and hence thenumber of communication paths available to link devices in any of thelinked vehicles. An automobile may be communicatively coupled to atrailer that it is towing. Two vehicles traveling together can be linkedin order to exchange messages, vehicle functional data, entertainmentprogramming, etc. For example, passengers in linked vehicles may jointlyplay electronic games or watch video programming. A vehicle disabledbecause of the failure of one or more devices may be rendered operablein tandem with a rescue vehicle to which it is linked by using thefunctioning devices in the rescue vehicle to provide the function toboth. Similarly, if a device becomes isolated in a vehicle because of afailure of a portion of the active network, communication to the devicemay be reestablished using a linked surrogate vehicle to providecommunication paths to the isolated device.

While all of the active elements forming an active network may includeradio frequency transmission capability, for inter-vehicle linking ofactive networks, as opposed to intra-vehicle linking of active elements,linking may be limited to selected ones of the active elements. Theseselected active elements may include security, authentication,encryption, etc. capability. Thus, while an active element within thevehicle may wirelessly link to virtually any other active element withinthe active network, active networks may be limited to linking viaparticular active elements. Moreover, the types and quantities of dataexchanged may be limited. For linked active networks with low securityand lacking encryption, the link may be limited to transmission ofnon-identifying vehicle operating data. For example, in a one-to-manybroadcast application, a vehicle's headlights may be modulated to signalon-coming traffic about a traffic event. In this case, the signalingvehicle's headlights are a first wireless interface, and a photo-diodeor similar device on the receiving vehicle is a second wirelessinterface. Many vehicles may report the event in this or similarfashion, and many other vehicles may receive the reported informationthus establishes a many-to-many multicast.

One of the many applications of linking of active networks is theability to upgrade systems by upgrading software within vehicles withouthaving the vehicle return to a repair facility. Vehicles may identifyupgraded software via the linking of active networks and request a copyof the upgraded software be communicated to the active network. Whilethis process may be made seamless and transparent to the vehicleoperator, safeguards may be included permitting the vehicle operator toauthorize any such sharing and implementation of such upgraded software.Navigation, entertainment, and other similar program data may be sharedvia the inter-vehicle linking of active networks.

FIG. 15 illustrates an alternate arrangement for wireless coupling ofactive networks across vehicles. A first vehicle 240 includes an activenetwork 242 including a plurality of active elements. Coupled to theactive network 242 is a wireless interface 244. A second vehicle 246includes an active network 248 including a plurality of active elements.The second vehicle 246 also includes a wireless interface 250. Eachwireless interface 244 and 250 includes a suitable transceiver, such asan optical or radio frequency transceiver, and each may also includeprocessing capability and memory. The wireless interfaces 244 and 250arbitrate the wireless linking of the active networks 242 and 248providing required authentication, security and encryption.

Referring now to FIG. 16, the active network 36 (FIG. 4) is adapted toinclude a core network portion 260. The core network portion 260includes a plurality of core active elements 262. The core activeelements 262 are communicatively coupled only to other active elements,whether core active elements 262 or other, peripheral active elements 40forming a peripheral portion of the active network 36. High-speed media264 provides interconnections between core active elements 262. In thismanner, data may be transferred through the core network portion 260 ata first, high data rate, and transferred to/from devices coupled to theactive network 36 at a second, slower data rate. Alternatively, theinterconnection of the core active elements may be made using multiplecommunication links providing enhanced communication capacity. Devicesare coupled to the active network via the peripheral active elements.

FIG. 17 illustrates the active network 36 adapted to include “fat pipe”members 270 and 272. Fat pipe members 270 and 272 provide directcoupling of the active element 274 to the active element 276 and theactive element 278 to the active element 280, respectively. The fat pipemembers 270 and 272 may be, and generally are high speed data carryingmembers adapted for particular applications, and may be particularlyadapted to provide scalability in an after-market arrangement, such ascoupling a DVD player to a video display. In that regard, the originalequipment active elements may be replaced with the active elements274-280 capable of handling the higher data capacity of the fat pipemembers 270 and 282. Alternatively, the fat pipe members 270 and 272 mayprovide scalability in original equipment applications. For example, thefabric 38 may be configured for a base level of vehicle options, whilepremium options are provided by adding the fat pipe members 270 and 272.

FIG. 18 illustrates the active network 36 adapted with additional activeelements 290 and 292 and connection media 294-302 coupling the activeelements 290 and 292 to the active network 36. FIG. 18 illustrates themanner in which active networks in accordance with the invention may beexpanded, by adding connection media and additional active elements tothe fabric as needed. If necessary, existing active elements may bereplaced with active elements having a sufficient number of ports to beable to add the connection media 294-302. Moreover, the connection media294-302 may have a higher data capacity than the existing connectionmedia 294-302. As will be further appreciated from the embodiments ofthe invention illustrated in FIGS. 17 and 18, the fabric includingeither the “fat pipe” members or the additional active elements does notneed to have a uniform configuration, and may have an asymmetricconfiguration.

FIGS. 19 and 20 illustrate alternative active network configurations. InFIG. 19, an active network 310 includes a ring 312 of interconnectedactive network elements (not depicted). A plurality of devices 314-322is communicatively coupled by interfaces 324-332, respectively to thering 312 in a multi-drop arrangement. Additionally, devices 320 and 322are coupled for peer-to-peer communications by communication link 344.Communication link 334 may be formed of any suitable media, includingwire, optical, radio frequency or combinations thereof. The device 320therefore may communicate with the device 322 via the network 312 ordirectly via the peer communication link 334.

In FIG. 20, an active network 340 includes a backbone 342 ofinterconnected active elements to which a plurality of devices 344-352is communicatively coupled by interfaces 354-362, respectively to thebackbone in a multi-drop arrangement. Additionally, devices 348 and 352are coupled for peer-to-peer communications by communication link 364.Communication link 364 may be formed of any suitable media, includingwire, optical, radio frequency or combinations thereof. The device 348therefore may communicate with the device 352 via the network 340 ordirectly via the peer communication link 364.

FIG. 21 illustrates several data packet configurations that may be usedin connection with active networks according to the embodiments of theinvention. As described, the active networks may be configured tooperate in accordance with TCP/IP, ATM, RapidIO, Infiniband and othersuitable communication protocols. These data packets include structureto conform to the standard required. A typical data packet, such as thedata packet 400 includes a header portion 402, a payload portion 404 anda trailer portion 406. As described herein, the active network and thenetwork elements forming the active network may contain processingcapability. In that regard, a data packet 410 includes along with aheader portion 412, payload portion 414 and trailer portion 416 anactive portion 418. The active portion may cause the network element totake some specific action, for example providing alternate routing ofthe data packet, reconfiguration of the data packet, reconfiguration ofthe network element, or other action, based upon the content of theactive portion. The data packet 420 includes an active portion 428integrated with the header portion 422 along with a payload portion 424and a trailer portion 426. The data packet 430 includes a header portion432, a payload portion 434 and a trailer portion 436. An active portion438 is also provided, disposed between the payload portion 434 and thetrailer portion 436. Alternatively, as shown by the data packet 440, anactive portion 442 may be integrated with the trailer portion 444 alongwith a payload portion 446 and a header portion 448. The data packet 450illustrates a first active portion 460 and a second active portion 458,wherein the first active portion 460 is integrated with the headerportion 452 and the second active portion 458 is integrated with thetrailer portion 456. The data packet 450 also includes a payload portion454. Certainly numerous other arrangements of the data packets for usewith the present invention may be envisioned.

The data, and particularly the data packets, sent within the activenetwork may be encrypted. The encryption function may be provided by theinterface of the device to the active network, e.g., interfaces 22-28(FIG. 1) or by the active network element of the active network to whichthe device is coupled. Data may be encrypted to ensure that it is notaltered as it is communicated within the active network, which may beimportant for the proper function of various safety systems of thevehicle or to ensure compliance with governmental regulation. A suitablepublic or private key encryption algorithm may be employed, and the datamay be encrypted before being packetized or the individual data packetsmay be encrypted after packetization. Moreover, detecting errors in thedata upon decrypting may provide an indication of an error or faultcondition in the active network along the route utilized by data packet,which caused the corruption of the data packet.

The active portion of the data packet may represent a packet state. Forexample, the active portion may reflect a priority of the data packetbased on aging time. That is, a packet initially generated may have anormal state, but for various reasons, is not promptly delivered. As thedata packet ages as it is routed through the active network, the activeportion can monitor time since the data packet was generated or timewhen the packet is required, and change the priority of the data packetaccordingly. The packet state may also represent an error state, eitherof the data packet or of one or more elements of the active network. Theactive portion may also be used to messenger data unrelated to thepayload within the network, track the communication path taken by thedata packet through the network, provide configuration information(route, timing, etc.) to active elements of the active network, providefunctional data to one or more devices coupled to the active network orprovide receipt acknowledgment.

The invention has been described in terms of several embodiments,including a number of features and functions. Not all features andfunctions are required for every embodiment of the invention, and inthis manner the invention provides an adaptable, fault tolerant, activenetwork architecture for vehicle applications. The features discussedherein are intended to be illustrative of those features that may beimplemented; however, such features should not be considered exhaustiveof all possible features that may be implemented in a system configuredin accordance with the embodiments of the invention.

1. In a vehicle comprising a first device and a second device, an activenetwork communicatively coupling the first and second devices, whereinthe active network comprises a fabric of active network elements suchthat each of the active network elements is interconnected to aplurality of other active network elements of the fabric of activenetwork elements via a corresponding plurality of point-to-pointconnections each of which connects no more than two active networkelements to one another, wherein the active network elements areconfigured to route data packets through the fabric of active networkelements to provide at least one communication path selected frommultiple potential communication paths between the first device and thesecond device.
 2. The vehicle of claim 1, wherein the active networksupports multiple, simultaneous communication paths between the firstand the second device.
 3. The vehicle of claim 1, wherein the activenetwork complies with an Internet protocol standard.
 4. The vehicle ofclaim 1, wherein the active network comples with asynchronous transfermode protocol.
 5. The vehicle of claim 1, wherein at least one of theactive network elements comprises a router.
 6. The vehicle of claim 1,wherein at least a portion of the active network elements are linkedelectronically.
 7. The vehicle of claim 1, wherein at least a portion ofthe active network elements are linked by radio frequency.
 8. Thevehicle of claim 1, wherein the active network elements are arranged inan array topology.
 9. The vehicle of claim 1, wherein the active networkcommunicatively couples at least one additional device to the first andsecond devices.
 10. Apparatus comprising: an active network of anautomobile configured to communicatively couple a first device of theautomobile and a second device of the automobile, wherein the activenetwork comprises a fabric of active network elements such that each ofthe active network elements is interconnected to a plurality of otheractive network elements of the fabric of active network elements via acorresponding plurality of point-to-point connections each of whichconnects no more than two active network elements to one another,wherein the active network elements are configured to route data packetsthrough the fabric of active network elements to provide at least onecommunication path selected from multiple potential communication pathsbetween the first device and the second device.
 11. The apparatus ofclaim 10, wherein the active network supports multiple, simultaneouscommunication paths between the first device and the second device. 12.The apparatus of claim 10, wherein the active network complies with anInternet protocol standard.
 13. The apparatus of claim 10, wherein theactive network complies with asynchronous transfer mode protocol. 14.The apparatus of claim 10, wherein at least one of the active networkelements comprises a router.
 15. The apparatus of claim 10, wherein atleast a portion of the active network elements are linkedelectronically.
 16. The apparatus of claim 10, wherein at least aportion of the active network elements are linked by radio frequency.17. The apparatus of claim 10, wherein the active network elements arearranged in an array topology.
 18. The apparatus of claim 10, whereinthe active network communicatively couples at least one additionaldevice to the first and second devices.
 19. A method comprising: addingat least one additional active element; adding connection media couplingthe at least one additional active element to an active network of anautomobile, wherein the active network is configured to communicativelycouple a first device of the automobile and a second device of theautomobile, wherein the active network comprises a fabric of activenetwork elements such that each of the active network elements isinterconnected to a plurality of other active network elements of thefabric of active network elements via a corresponding plurality ofpoint-to-point connections each of which connects no more than twoactive network elements to one another, and wherein the active networkelements are configured to route data packets through the fabric ofactive network elements to provide at least one communication pathselected from multiple potential communication paths between the firstdevice and the second device.
 20. The method of claim 19, wherein theactive network communicatively couples at least one additional device tothe first and second devices.